Intermittent dialysis method and apparatus therefor



References Cited Boen et aL-Trans. Amer. Soc. Art. inter. Orgs. vol. Vlll. 1962' PP- 256-262.

proved method peritoneal dialysis treatments McDonald-Trans. Amer. Soc. Art. Inter. Orgs. vol. Xl. I965. P1 83-85.

Miller et aL-Trans. Amer. Soc. Art. lnter. Orgs. vol. Xll. 1966. pp. 98-105.

Primary Examiner-Dalton L. Truluck Attorney-Barnes, Kisselle, Raisch and Choate ABSTRACT: This invention relates to an im and apparatus for performing which uses an initially unsterilized dialysis liquid and reuses a major portion of the dialysis liquid for several cycles of the treatment. The apparatus comprises a plurality of receptacles, a vacuum pump, a pressure pump, a bacterial filter and a system of valves; the various components of the system bein automatically cycled to accomplish the ste method.

James H. De Vries Ann Arbor, Michigan App]. No. 704,729

Feb. 12, 1968 [45] Patented Dec. 8, 1970 Sarns, Inc.

Ann Arbor, Michigan a corporation of Michigan INTERMITTENT PERITONEAL DIALYSIS METHOD AND APPARATUS THEREFOR 11 Claims, 1 Drawing Fig.

United States Patent [72] Inventor [22] Filed [73] Assignee g ps of the improved 32 Q VACUUM T0 PATIENT TANK E m S Ev L m D REGULATOR FRESH DIALYSATE CYCLER g FILTER l-Il- To 6/ PATIENT 1 INTERMITTENT PERITONEAL DIALYSIS METHOD AND WAPPARAIQSIHEREFQK.

BACKGROUND OF THE INVENTION This invention relates to an improved method of and automatic apparatus for a peritoneal dialysis treatment which utilizes an initially unsterilized dialysis liquid. Peritoneal dialysis is a medicaltreatment which comprises the washing or flushing of the peritoneal chamber of the abdomen with a quantity of liquid, generally a salt solution of some kind, which is introduced into and removed from the cavity through a catheter for the purpose of removing poisonous substances from the human body. a

In brief, the method of this invention uses a first measured quantity of unsterilized dialysis solution which is sterilized and then injected under pressure into a patients peritoneal cavity, a vacuum is then used to remove the solution from the peritoneal cavity and a portion of the returned solution is deleted or disposed of and the remainder of the returned solution is mixed with a second measured quantity of unsterilized solution with the resulting mixture being subjected to the above steps seriatim until the treatment is completed. In the preferred embodiment of this method the volume of the deleted portion of the returned liquid is equal to the volume of the second quantity of unsterilized solution so that it is possible to determine if any dialysis solution has been left in or if any excess fluid has been removed from the patients peritoneal cavity when the treatment is completed. The apparatus of this invention uses a plurality of reservoirs, a bacterial filter and an arrangement of pumps and valves which are automatically cycled to repetitively perform the steps of the improved method. The method and apparatus of this inventionuse an initially unsterilized dialysis solution and reuse a substantial portion of the solution on each cycle of the method and apparatus.

The prior art references known to the inventor are the A. Gasca et al. US. Pat. No. 2,720,879, An Automatic Peritoneal Dialysis Machine: Preliminary Report, by Harold P. Mac- Donald .Ir., Vol. XI Transaction of the American Society for Artificial Internal Organs, I965 at page 83, and Chronic Peritoneal Dialysis, by Norman Lasker et al. Vol. XII Transaction of the American Society for Artificial Internal Organs, I966 at page 94. These references disclose various methods and devices for performing peritoneal dialysis, but they do not disclose or anticipate either a method or automatic apparatus which has the combined advantages of using both an initially unsterilized dialysis solution andof reusing a portion of the solution during each cycle of the treatment.

DESCRIPTION OF THE INVENTION of dialysate that has been injected and the volume that has been removed from the peritoneal cavity of the patient during a peritoneal dialysis treatment.

Another object of this invention is to provide a method of and an apparatus for peritoneal dialysis which utilizes unsterile dialysis solution, thereby lowering the expense of a peritoneal dialysis treatment.

Another object of this invention is to provide an apparatus having a sterile closed loop for performing a peritoneal dialysis treatment. 7

Another object of this invention is to provide an apparatus Another object of this invention is to provide an apparatus for peritoneal dialysis which limits the maximum quantity of an injection of dialysis solution to a safe level.

Other objects and features of this invention will be apparent from the following description and claims in which there is found the manner of making and using the invention and the best mode contemplated by the inventor for carrying out the invention.

A drawing accompanies this disclosure and schematically shows the arrangement and relationship of the various components of this apparatus.

REFERRING TO THE DRAWING In the drawing, a fresh unsterile dialysis fluid reservoir 10 is shown in liquid communication with a holding reservoir 12, the liquid communication being controlled by a valve 14 having suitable conduits. The reservoir 12 has a small air vent 13 to aid in the filling of the reservoir. The holding tank 12 is connected to an administration reservoir 16 by suitable conduits and a valve 18. The administration reservoir 16 has a level in dicator designated generally as 20 which is comprised of a float 22, a stem 24 and a scale 26. An overflow conduit 28 is connected to the upper portion of the administration reservoir 16 and a dump valve 30 is connected through suitable conduits to the bottom of the administration reservoir 16. A vacuum means such as a vacuum pump 32 and a vacuum regulator 34 are connected through suitable conduits to the top of the administration reservoir 16 and a deleting means such as a reservoir 36 is connected to the upper portion of the administration reservoir 16 by suitable conduits and a valve 38. A fluid inlet connector 40 is coupled to the upper portion of the deleting tank 36 by suitable conduits: and a dump valve 42 is connected to the bottom of the deleting tank 36. An exhausted dialysis solution reservoir 44 is positioned below the administration reservoir 16 and the deleting reservoir 36 so that a liquid can flow by gravity from the deleting reservoir 36 i into the reservoir 44 when the. valve 42 is open, and a liquid for peritoneal dialysis having an automatic cycling and control device, thereby reducing the amountof time that is required to supervise the treatment of a patient.

can also flow by gravity from the administration reservoir 16 into the reservoir 44 when either the valve 30 is opened or a dialysis solution passes through the overflow conduit 28. In the preferred embodiment of this apparatus a bacterial trap (not shown) is placed in the overflow conduit 28. A handoperated dump valve 46 is positioned in the bottom of the reservoir 44 to facilitate emptying the reservoir. The reser' voirs 10 and 12 are also positioned so that a liquid will flow by gravity from reservoir 10 to reservoir 12 and from reservoir 12 to the administration reservoir 16 when the appropriate valves 14 and 18 are opened. The holding reservoir 12 and the administrationreservoir 16, when consideredas a unit, comprise a measuring means for determining a specific quantity of dialysis solution to be injected into a patients peritoneal cavity. The fresh dialysate reservoir 10 could also be considered to be a part of this measuring means.

In the preferred embodiment of this apparatus an inlet 48 of a variable flow rate pump 50 or liquid moving means that provides essentially a constant output at each flow rate, such as a Sarns electronic drive pump manufactured by Sarns, Inc., 1354 N. Main Street, Ann Arbor, Michigan, is connected by a suitable conduit to the bottom of the administration reservoir 16 and an outlet 52 of the pump 50 is connected to a prefilter 54 by a suitable conduit. A' tachometer 56 is responsive to the speed of the variable flow rate pump and can be calibrated to indicate the flow rate of the pump. The prefilter 54 is connected by a suitable conduit to an optional or alternate flow meter 58 which is connected by a suitable conduit to the inlet of a sterilizing means such as a bacterial filter 60, the outlet of which is connected by suitable conduits to a pressure relief switch 61 and to a fluid outlet connector 62. The pressure relief switch limits the pressure'of the dialysis solution flowing into a patients peritoneal cavity to a safe level. The tachometer 56 or optional flow meter 58 or both provide a visual indication of the flow rate to assist in adjusting the pump 50. The flow meter 58 also provides a means of monitoring the actual flow rate. This apparatus would perform satisfactorily if the flow rate of the pump 50 or liquid moving means was fixed, but a variable flow rate pump provides greater flexibility in tailoring the output and cycle of the apparatus to the specific requirements of each patients treatment. The prefilter 54 is positioned prior to the bacterial filter to remove any large particles that might be present in the unsterile dialysis fluid. The sterilizing means or bacterial filter 60 removes bacteria from the dialysis fluid, thereby sterilizing the fluid. A suitable bacterial filter is an autoclavable Millipore Filter with a l42-millimeter diameter filter membrane having 0.22 micron poresize openings in the membrane material. Such a filter can be purchased from the Millipore Corp., Bedford, Massachusetts.

An equivalent filter can also be purchased from the Gelman instrument Co., Ann Arbor, Michigan.

in the preferred embodiment of the apparatus the valves 14, 18, 30, 38 and 42 are all solenoid operated electrically controlled valves. A cycling unit' 64 controls the operation of all of the solenoid valves and of the vacuum pump 32 and the pressure pump 50. When the solenoid valves are deactivated, they are in the closed position. The cycler 64 performs essentially six steps or operations, the first, fifth and sixth of which are manually initiated, the second, third and fourth constituting the automatic cycle, of which the second and third are controlled by individually adjustable timers and the fourth is controlled by a delayed action relay. In the first step the valves 14 and 18 are activated by'a manually controlled switch means and all the other valves are closed and both pumps are deactivated. In the second step the valve 1.4 is activated or opened and the pressure pump 50 is activated and controlled by one of the timers of the cycler 64, the remaining valves are closed and the vacuum pump is deactivated. inthe third step the valves 14 and 38 are activated or opened and the vacuum pump is activated and controlled by the second timer in the cycler 64 with the remaining valves being deactivated or closed and the pressure pump 50 being deactivated. In the fourth step the valves 18 and 42 are activated or opened and the' remaining valves are deactivated or closed and both pumps 32 and 50 are also deactivated. During the fifth step which is manually initiated and controlled, solenoid valves 18, 30, 38 and 42 are activated or opened and both of the pumps 32, 50 are deactivated. During the manually initiated and controlled sixth step, all of the solenoid valves are activated or opened and both of the pumps are deactivated.

To use this apparatus in performing a peritoneal dialysis, a suitable catheter is inserted into a patient's peritoneal cavity and connected by suitable liquid conduits to the fluid inlet coupler 40 and fluid outlet coupler 62 of the apparatus. Fresh unsterilized dialysis fluid is placed in the reservoir and the manual switch means of the cycler 64 is actuated which causes valves 14 and 18 to be opened, thereby allowing the unsterile dialysis fluid to flow into the administration reservoir 16 from the unsterile dialysate reservoir 10. Whenthe proper amount of dialysis fluid to be injected into the peritoneal cavity has flowed into the administration chamber, the switch means of the cycler 64 is returned to its first position, thereby causing the valves 14 and 18 to be deactivated and the flow of fluid into the administration chamber 16 to cease. The amount of fluid in the administration chamber is indicated by the level indicator 20. After the proper amount of fluid has been placed in the administration chamber 16, the switch means of the cycler 64 is turned to the automatic position which initiates step two of the cycle which causes the pressure pump 50 to be activated, thereby pumping the dialysis fluid from the administration tank 16 through the prefilter 54, optional flow meter 58, bacterial filter 60 where the dialysis solution is sterilized, output connector 62, catheter and into the patients peritoneal Cavity. The holding reservoir 12 will be filled after the first step since valve 18 is closed and valve 14 remains open. The first timer of the cycler 64 is adjusted to provide sufficient pumping time to allow all of the dialysis fluid in the administration chamber 16 to be pumped into the patients peritoneal cavity. After the predetermined amount of time controlled by the first timer has expired, the cycler 64 automatically switches to step three, thereby deactivating the pressure pump 50 and activating the vacuum pump 32 and valve 38 thereby applying a slight vacuum to the administration reservoir 16, deleting reservoir 36, fluid inlet coupling 40 and thecatheter which causes the dialysis fluid to be removed from the patients peritoneal cavity. The dialysis fluid that is removed from the patients peritoneal cavity first fills the deleting reservoir and then the excess flows into the administration tank during the third part of the cycle which is controlled by the second adjustable timer of the cycler 64. After the expiration of the amount of time predetermined by the second timer, the cycler 64 intitiates the fourth step of the cycle which deactivates the valve 38 and the vacuum pump 32 and activates or opens the valves 18 and 42 which allows the fluid in the holding reservoir 12 to flow into the administration reservoir 16 and the fluid in the deleting reservoir to flow into the used or spent dialysate reservoir 44. Since the volumetric capacity of the holding reservoir 12 is equal to the capacity of the deleting reservoir 36, the amount of fluid that is left in the administration reservoir 16 upon completion of step four by the cycler 64 is equal to the volume of fluid that was returned from the peritoneal cavity of the patient. When this volume is compared with the amount of fluid that was initially injected into the peritoneal cavity, it can be determined whether the proper amount of fluid has been removed from the cavity. The delayed action relay of the cycler 64 provides a sufficient time interval for the dialysis fluid to flow from both the holding reservoir 12 and the deleting reservoir 36 before it automatically reinitiates step two of the cycler. The cycler 64 continues to repeat steps two,- three and four until the cycling is manually interrupted by actuation of the switch means of the cycler. Manually activated step five opens valves 18, 30, 3 8 and 42 which allows the holding, deleting and administration reservoirs to drain into the spent dialysate reservoir. By manually actuating the cycler switch means, step six can be initiated in which all of the solenoid operated valves are activated or opened and both of the pumps 32, 50 are deactivated. This manually controlled step allows all of the reservoirs of the apparatus to be drained for purposes of storing or cleaning the apparatus.

in the preferred embodiment of this apparatus the holding 12 and deleting 36 reservoirs have equal volumetric capacities so that the amount of dialysis solution that remains in the ad ministration reservoir 16 after the treatment is completed can be compared with the volume of dialysis solution that was used to initiate the treatment cycle so that it can be determined if any dialysis solution remains in or if an excess amount 'of fluid has been removed from the patients peritoneal cavity.

Since the volume of the two reservoirs 12 and 36 are equal, the amount of solution removed by the deleting reservoir during each cycle should be equal to the amount of solution added by the holding solution during each cycle. In the preferred embodiment of this device the overflow conduit 28 is positioned in the administration reservoir 16 so that the reservoir will hold 2 liters of solution before overflowing. This limits the amount of solution that can be injected by the ap paratus to a safe level. Normally, one liter of solution is initially placed in the administration reservoir 16 for performing a peritoneal dialysis treatment. In the preferred embodiment of this apparatus the volumetric capacity of the deleting and holding reservoirs is 200 millimeters; therefore, the apparatus with the normal 1 liter initial charge reuses about four-fifths of the dialysis solution of the preceeding cycle on the next cycle. In the unusual situation where the administration reservoir 16 has overflowed into the spent dialysate tank, it is still possible to determine if any dialysis solution remains in or if an excess amount of fluid has been removed from the patients peritoneal cavity. In the overflow situation this determination is made by manually switching the cycler to step five which causes the holding, deleting and administration reservoirs to drain into the spent dialysate reservoir. The volume of solution in the spent dialysate reservoir is then compared with the initial volume of unsterile dialysate that was in the fresh dialysate reservoir just prior to initiating the treatment by starting cycle one. Graduated containers or other suitable means can be used as reservoirs l0 and 44 to assist in determining these volumes.

Since this apparatus is automatically cycled by the cycler 64, the amount of time that is required to supervise a peritoneal dialysis treatment will be substantially reduced. With this apparatus the cost of the dialysis solution that is required for a peritoneal dialysis treatment will be reduced because the apparatus uses unsterilized dialysis solutions which are sterilized by the bacterial filter of the apparatus and also because the apparatus reuses a portion of the dialysis solution of previous cycles on every cycle after the first one. In the preferred embodiment of this apparatus, if the administration chamber is initially filled to the 1 liter or 1,000-cc. level approximately four-fifths or 800-cc. of dialysis solution will be reused on each cycle with the remaining 200cc.s of the used dialysis solution being dumped into the spent dialysate reservoir 44 from the deleting reservoir 36 and being replaced by ZOO-cc. of fresh dialysate solution from the holding reservoir 12. As well as reducing the cost of the dialysis fluid used in a peritoneal dialysis treatment, this arrangement also reduces the number of times that the fresh unsterilized dialysate reservoir must be refilled during a treatment period. With this apparatus the sterilized dialysis fluid passes immediately from the biological filter to the peritoneal cavity of the patient and is returned from the peritoneal cavity directly to the administration reservoir 16 from which it must again pass through the bacterial filter 60 before reentering the peritoneal cavity of the patient; therefore, this apparatus provides a sterilized closed loop for performing a peritoneal dialysis which substantially reduces the risk to the patient of having any bacterial activity initiated within the peritoneal cavity by the use of unsterilized or contaminated dialysis fluids. As was mentioned above, this apparatus also provides a means of determining if the proper amount of fluid has been removed from the peritoneal cavity when the treatment is completed and also a means of preventing an excessive volume of dialysis fluid from being injected into the peritoneal cavity.

Iclaim:

1. An apparatus for intermittent peritoneal dialysis which comprises in combination; an administration reservoir, meav suring means for determining a specific quantity of an unsterilized dialysis liquid connected for liquid communication with said administration reservoir and adapted to receive unsterilized dialysis liquid from a source of said liquid, sterilizing means connected for liquid communication with said administration reservoir for sterilizing a dialysis liquid and having a sterilized dialysis liquid outlet, pump means connected for liquid communication with both said administration reservoir and said sterilizing means for moving a dialysis liquid from said administration reservoir through said sterilizing means and said liquid outlet, a return liquid dialysate inlet connected for liquid communication with said administration reservoir, deleting means connected for liquid communication with said return inlet for deleting a portion of a dialysate liquid flowing from said return inlet, and vacuum means connected for communication with said administration reservoir to urge a dialysate liquid to flow through said return inlet and into said administration reservoir.

2. An apparatus for peritoneal dialysis as defined in claim 1' which also comprises cycling means sequentially controlling said pump means to move dialysis liquid in said administration reservoir through said sterilizing means and said liquid outlet, and after all of said liquid from said administration reservoir has passed through said outlet, said vacuum means to urge a return dialysate liquid to flow through said return inlet and into said administration reservoir, said measuring means to inject a specific quantity of unsterilized dialysis liquid into said administration reservoir, and said deleting means to delete a portion of the return dialysate liquid liquid.

3. An apparatus for peritoneal dialysis as defined in claim 1 in which said sterilizing means comprises a bacterial filter.

4. An apparatus for peritoneal dialysis as defined in claim 1 in which the quantity of liquid injected by said measuring means into said administration reservoir is equal to the quantity of liquid deleted by said deleting means.

5. An apparatus for intermittent peritoneal dialysis which comprises in combination; an administration reservoir, a holding reservoir in liquid communication with said administration reservoir and adapted to receive unsterilized dialysis liquid from a supply of said liquid and to inject a specific quantity of liquid into said administration reservoir, sterilizing means connected for liquid communication with said administration reservoir for sterilizing a dialysis liquid and having a sterilized dialysis liquid outlet, means connected for liquid communication with both said administration reservoir and said sterilizing means for moving a liquid from said administration reservoir through said sterilizing means and said liquid outlet, a return liquid dialysate inlet connected for liquid communication with said administration reservoir, deleting means interposed between and connected for liquid communication with both said return inlet and said administration reservoir for deleting a portion of a dialysate flowing from said return inlet to said administration reservoir, and vacuum means connected for communication with said administration reservoir to urge a return dialysate to flow through said return inlet and deleting means and into said administration reservoir.

6. An apparatus for peritoneal dialysis as defined in claim 5 which also comprises a fresh unsterile dialysis reservoir connected for liquid communication with said holding reservoir to provide the supply of unsterilized dialysis liquid.

7. An apparatus for peritoneal dialysis as defined in claim 6 in which said sterilizing means comprises a bacterial filter.

8. An apparatus for peritoneal dialysis as defined in claim 5 in which said sterilizing means comprises a bacterial filter.

9. An apparatus for peritoneal dialysis as defined in claim 5 in which said deleting means comprises a deleting reservoir having a valve means controlling said liquid communication with said administration reservoir and said deleting reservoir has a liquid outlet controlled by a valve means.

10. An apparatus for peritoneal dialysis as defined in claim 9 in which the volume of said holding reservoir is equal to the volume of said deleting reservoir.

11. A method of performing an intermittent peritoneal dial ysis treatment which comprises the steps of determining and sterilizing a first quantity of unused unsterilized dialysis liquid, introducing said first quantity of unused sterilized dialysis liquid into a patients peritoneal cavity, and after all of said first quantity of unused sterilized dialysis liquid has been introduced into a patients peritoneal cavity and before introducing any additional dialysis liquid into the peritoneal cavity, removing substantially all of said first quantity of liquid from the patients peritoneal cavity, determining and separating a second quantity of dialysis liquid from said removed first quantity of dialysis liquid, determining and adding a third quantity of unused unsterilized dialysis liquid to the removed dialysis liquid remaining after said second quantity has been separated, sterilizing all of the mixture of said remaining removed dialysis liquid and said third quantity of unused unsterilized dialysis liquid, and introducing the sterilized mixture under pressure into the peritoneal cavity with these steps being repeated until the treatment is completed. 

